Treatment of fibres

ABSTRACT

Synthetic textile materials, such as polyamides, polyesters, polyacrylonitrile, polyvinyl alcohol, and cellulose triacetate, are treated with an ester containing on average, at least two mercaptan groups per molecule, which is then cured, in order to impart a better handle and improved antisoil properties. Typically, the ester is prepared by the reaction of A. A COMPOUND CONTAINING AT LEAST TWO CARBOXYLIC ACID GROUPS B. A COMPOUND CONTAINING AT LEAST TWO ALCOHOLIC HYDROXYL GROUPS AND, OPTIONALLY, C. A COMPOUND CONTAINING NOT MORE THAN ONE CARBOXYLIC ACID GROUP OR ALCOHOLIC HYDROXYL GROUP, ESPECIALLY A MONOMERCAPTOMONOCARBOXYLIC ACID OR A MONOMERCAPTOMONOHYDRIC ALCOHOL.

United States Patent [191 Barber et al.

[451 Sept. 17,1974

[ TREATMENT OF FIBRES [75] Inventors: Albert John Barber, Sale; Derek James Rowland Massey, Linton, both of England; James McCartney, Banbridge, Northern Ireland; Kenneth Winterbottom, Whittlesford, England [73] Assignee: Ciba-Geigy AG, Basle, Switzerland [22] Filed: Apr. 12, 1972 [21] Appl. No.: 243,470

[30] Foreign Application Priority Data Apr. 19, 1971 Great Britain 9765/71 [52] U.S. Cl..... l17/l38.8 A, 8/ll5.6, 117/138.8 B, l17/l38.8 F, 117/1388 N, 117/138.8 UA,

117/138.8 PV,117/139.5 A

[51] Int. Cl. D06m 15/48, D06m 15/08 [58] Field of Search 8/115.6, 185; 117/139.5 A, 11'7/1388 B, 138.8 F, 138.8 N, 138.8 A

[56] References Cited UNITED STATES PATENTS 2,461,920 2/1949 Pratt 260/828 X 2,917,410 12/1969 Vitalis l17/139.5 X 3,476,697 11/1969 Clements .1 117/139.5 X

Hanson 8/115.6 X

3,690,942 9/1972 Vandermaas et a1 117/139.5 X 3,703,352 11/1972 Dobinson et a1 117/141 X 3,706,527 12/1972 Dobinson et a1 8/115.6 X 3,706,528 12/1972 Dobinson et a1 117/1394 X Primary Examiner-Herbert B. Guynn Attorney, Agent, or Firm-Joseph G. Kolodny; Edward McC. Roberts; Prabodh I. Almaula [57] ABSTRACT Synthetic textile materials, such as polyamides, polyesters, polyacrylonitrile, polyvinyl alcohol, and cellulose triacetate, are treated with an ester containing on average, at least two mercaptan groups per molecule, which is then cured, in order to impart a better handle and improved antisoil properties.

10 Claims, No Drawings TREATMENT ()F'FIBRES This invention relates to a process for modifying synthetic materials in fibrous form, and to materials so treated.

It is well known to treat textiles comprising synthetic fibres with softening agents, such as polyethylene emulsions or adducts of ethylene oxide with phenols or amines, to improve the handle of the textile. These softening agents suffer from the disadvantage of failing to exhaust onto the textile. Since the softening agent is normally applied to a wet fabric just after scouring or dyeing has been carried out, a high concentration of softening agent is required to give the desired uptake, and a high proportion of this softening agent is subsequently removed from the material on washing. The process is therefore wasteful.

It has now been found that, by the use of certain esters containing mercaptan (-SH) groups, synthetic f1- brous materials having improved properties, in particular textiles having a fuller, softer, and more resilient handle, and improved antisoil properties (including enhanced soil-release, and reduced soil-redeposition) and antistatic properties, can be obtained. These esters may also serve as spinning lubricants and as knitting and weaving oils. It has also been found that, surprisingly, these substances can exhaust onto the fibres and the effects are resistant to washing and dry cleaning.

Accordingly, the present invention provides a process for modifying synthetic fibres which comprises 1. treating the fibres, in the absence of keratinous material, with an ester which contains on average at least two mercaptan groups per molecule and which is obtainable by the reaction of a. a compound containing at least two carboxylic acid groups,

b. a compound containing at least two alcoholic hydroxyl groups, and optionally,

c. a compound containing not more than one car boxylic acid group or alcoholic hydroxyl group, at least one of(a) and (b), and (c) if used, having one or more mercaptan groups, and

2. curing the ester on the fibres.

The present invention further provides synthetic fibrous materials, free from keratinous materials and bearing thereon an ester as aforesaid, in the cured or still curable state.

Synthetic fibres which may be subjected to the process of the present invention may be in the form of loose fibres, yarns, threads, woven, non-woven and knitted fabrics and garments, woven and tufted carpets, and needle-punched and other mechanically formed fibrous floor covering materials, and are preferably polyamides (nylons), polyesters, polyacrylonitrile, and polyvinyl alcohol. The term synthetic fibres is taken herein to include man-made fibres of cellulosic origin in which all three available hydroxyl groups per anhydro-gluco unit have been chemically modified, e.g., by acylation, etherification, or cyanoethylation. Thus, cellulose triacetate is regarded, for the purposes of this invention, as a synthetic material.

Mixtures of two or more synthetic fibrous materials, or blends with cellulosic materials, may also be treated, but blends of these materials with keratinous fibres are not included within the scope of the present invention.

Preferred esters for use in the process according to the invention are those esters containing on average not more than six mercaptan groups per molecule, and they usually have an average molecular weight of between 400 and 10,000, but, if desired, esters having an average molecular weight of up to 20,000, or even 40,000 may be used.

Such esters may be those obtainable by the reaction, in any desired sequence, of

d. a monomercaptomonocarboxylic acid or a monomercaptomonohydric alcohol,

e. a compound containing two, but not more than two, alcoholic hydroxyl groups per molecule, and

f. a compound containing, per molecule, at least three carboxylic acid groups.

If desired, components (e) and (f) may be caused to react to form a hydroxyl or carboxyl-terminated ester and this is then esterified with (d).

Such esters may also be those obtainable by the esterification of g. a monomercaptodicarboxylic acid with h. a compound containing at least two but not more than six alcoholic hydroxyl groups per molecule and, optionally,

i. a dicarboxylic acid containing no mercaptan group,

or an anhydride of such an acid, or

j. a monocarboxylic acid, preferably a monomercaptomonocarboxylic acid, or

k. a monohydric alcohol, preferbly a monomercaptomonohydric alcohol.

Similarly, there may be employed esters obtainable by the reaction, in any desired sequence, of d. a monomercaptomonocarboxylic acid, or a monomercaptomonohydric alcohol 1. a compound containing at least three alcoholic hydroxyl groups per molecule, and

m. a compound containing two, but not more than two, carboxylic acid groups per molecule.

As those skilled in the art of making polyesters will appreciate, a carboxylic anhydride may be used in place of the corresponding carboxylic acid while a 1,2- epoxide may be substituted for an alcohol, one epoxide group corresponding to two alcoholic hydroxyl groups.

The esters are prepared in a known manner, preferably by heating the reactants together in the presence of a catalyst such as a strong acid (especially an anion exchange resin, toluene-p-sulphonic acid, or 50 percent sulphuric acid), and of an inert solvent, such as toluene, xylene, trichloroethylene, or perchloroethylene, with which water formed in the reaction can be removed as an azeotrope.

Substances containing at least two carboxylic acid groups, or anhydrides thereof, which may be used as compound (a) include succinic, adipic, phthalic, hexahydrophthalic, sebacic, malic, citric, tricarballylic, pyromellitic, and dimerised or trimerised fatty acids, and their anhydries (where existing), and thiomalic acid, HOOCCH CH(SH)COOH, otherwise known as mercaptosuccinic acid.

Monomercaptomonocarboxylic acids used as component (d) are usually of formula HOOC-R-SH, where of the radical R. Preferably they are also of formula HOOC-C,H ,-SH, where r is a positive integer of from 1 to as high as 18 or even 24. There may be thus be used mercaptoundecylic acid, mercaptostearic acid and especially thioglycollic acid and 2- and 3- mercaptopropionic acid, i.e., r in the above formula is l or 2. Mercaptan-containing aromatic acids such as oand pmercaptobenzoic acids may also be used.

Monomercaptomonohydric alcohols used as component (d) commonly have the general formula HO-R- SH, where R denotes a divalent organic radical, the HO group and the ---SH group being directly bound to carbon atoms of the radical R. Preferably they are also of formula HO-C,H ,-SH, where t is a positive integer of from 2 to 18 and especially preferred are those of the foregoing formula where t is 2 or 3, such as Z-mercaptoethanol, l-mercaptopropan-2-ol, and 2-mercaptopropan-l-ol, but substances such as 1- chloro-3-mercaptopropan-2-ol may also be used.

Compounds containing at least three carboxylic acid groups, or anhydrides thereof, which may be used as component (f) include citric acid, tricarballylic acid, pyromellitic acid and trimerised linoleic acid and their anhydrides (where existing).

The monomercaptodicarboxylic acid (g) is usually of formula where R" represents a trivalent aliphatic or alicyclic radical, the indicated carboxyl group and mercaptan group being directly linked to a carbon atom or carbon atoms of the group R", and preferably it is thiomalic acid.

The substances containing at least two alcoholic hydroxyl groups (b,e,h,l) include ethylene glycol, propylene glycol, propane-1,3-dio1, butane-1,2-diol, butanel,3-diol, butane-1,4-diol, hexane-1,6-diol, poly(oxyethylene) glycols, poly(oxypropylene) glycols, poly- (oxybutylene) glycols, poly(oxy-l 1 -dimethylethylene) glycols, poly(epichlorohydrins), glycerol, 1,1 ,1- trimethylolethane, l, l l -trimethylolpropane, hexane- 1,2,5-triol, hexane-1,2,6-triol, 3-hydroxymethylpentane-2,4-diol, pentaerytl'iritol, mannitol, sorbitol, and adducts of ethylene oxide or propylene oxide with such alcohols, including mixed polyhydric polyethers obtained by treating an initiator containing active hydrogen, such as ethylene glycol, with, say, propylene oxide, and then tipping the adduct with a second alkylene oxide, say, ethylene oxide.

Mono-1,2-epoxides which may be used in place of a dihydric alcohol include: ethylene oxide, propylene oxide, butylene oxide, l,l-dimethylethylene oxide, epichlorohydrin; glycidyl ethers of alcohols (such as nbutyl and iso-octyl glycidyl ethers) or of phenols (such as phenyl and p-tolyl glycidyl ethers), N-glycidyl compounds (such as N-glycidyl-N-methylaniline or N-glycidyl-n-butylamine), and glycidyl esters of carboxylic acids (such as glycidyl acetate).

In place of trihydric and higher alcohols there may be used monoepoxymonohydric alcohols such as glycidol, or a diepoxide such as a diglycidyl ether of an alcohol or a phenol.

The dicarboxylic acids containing no mercaptan group (i) which may be used are generally of the formula HOOC-R -COOH, whereR represents a divalent aliphatic, aromatic, or alicyclic residue, and include succinic, adipic, phthalic, hexahydrophthalic, sebacic, and malic acids, and dimerised fatty acids or their anhydrides. Although they can be used, ethylenicallyunsaturated dicarboxylic acids are not preferred.

The dicarboxylic acids (m) and their anhydrides may be selected from those listed above for (i) and also the mercaptan-containing dicarboxylic acids (g) and their anhydrides.

It is often desirable, when preparing a polymercaptan ester for use in the present invention to incorporate a monofunctional compound such as a monocarboxylic acid (j) or a monohydric alcohol (k) as a chainterminator. Examples of these are aliphatic alcohols such as methanol, ethanol, 2-ethylhexanol, 2- methoxyethanol, and monoethyl ethers of poly(oxyethylene) glycols and poly(oxypropylene) glycols; cycloaliphatic alcohols such as cyclohexanol; aliphatic carboxylic acids such as acetic acid, Z-ethylhexanoic acid, stearic acid, and oleic acid; and aromatic acids such as benzoic acid. As already indicated, it is especially advantageous to use as the chain-terminator a compound which contains a mercaptan group, examples being monomercaptomonocarboxylic acids and monomercaptomonohydric alcohols and, more specifically, thioglycollic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 2-mercaptoethanol, and 2-mercaptopropan-b 1-01.

The polymercaptan esters are, in general, known substances (see US. Pat. Nos. 2,456,314, 2,461,920, 2,914,585, and 3,138,573, French Patent Specification No. 1503633 and British Specification No. 941829).

The preferred polymercaptan esters used in the process of the present invention contain, directly attached to carbon atoms, an average n groups of formula )i, CO )1. Z )1, CO Y S H i where a and b are each zero or 1 but are not the same,

n is an integer of at least 1 and at most 6,

Y and Z each represent a divalent organic radical,

and

X represents a divalent organic radical which must contain an Sl-l group when n is 1.

More specifically, the average structures of the preferred esters can be represented by one of the formulae XVI where R denotes the residue of an aliphatic, cycloaliphatic, or aromatic dicarboxylic acid after removal of the two carboxyl groups,

R denotes the residue of an aliphatic, araliphatic, or

cycloaliphatic diol after removal of the two hydroxyl groups,

R denotes an organic radical containing at least two carbon atoms and directly linked through carbon atoms thereof to the indicated mercaptanterminated ester chains,

R denotes the residue of an aliphatic, cycloaliphatic,

or aromatic dicarboxylic acid containing a mercaptan group, after removal of the two carboxyl groups,

m is an integer of at least 1,

p is an integer of at least 2, and

R, r, and t have the meanings previously assigned.

It will be understood that formulae II to XVII represent the average structure of the esters. Because of incomplete esterification, other substances may also be present. Further, as already indicated, not all units designated R, R, and R to R need be the same.

Many of the esters are insoluble in water but can be applied as aqueous dispersions or emulsions. They may also be applied from organic solvents, for example lower alkanols (such as ethyl alcohol), lower ketones (such as ethyl methyl ketone), xylene, and halogenated hydrocarbon I solvents, especially chlorinated and/or fluorinated hydrocarbons containing not more than three carbon atoms such as the dry cleaning solvents, carbon tetrachloride, trichloroethylene, and perchloroethylene.

The amount of the ester to be used depends on the effect desired. For most purposes a pick-up of from 0.1 4 to 1 percent, and at most 10 percent, by weight based on the material to be treated is preferred. The handle of the treated material will, of course, depend on the amount of ester employed and by simple experiment the least amount required to give the desired effect may readily be determined. Further, the composition and the construction of the fabrics, also influence the amount of ester required.

If desired, the ester may be used in conjunction with other agents which can be made to cross-link on the fibres, e.g., aminoplasts and polyepoxides.

The desired effects may not be fully obtainable until substantially all the ester has cured. At room temperatures (say, 20C) this may take from five to ten days or even longer, but occurs much more rapidly at higher temperatures. The curing reaction may also be accelerated greatly by a catalyst and generally it is preferred to add the catalyst to the material to be treated at the same time as the ester is applied although it may be added before or afterwards if desired. The curing time can be controlled by selecting an appropriate catalyst and the choice of curing time will depend on the particular application of the process according to the invention. The catalysts may be bases, siccatives, oxidative 5 curing agents, sulphur, sulphur-containing organic compounds, salts and chelates of heavy metals, and free-radical catalysts or combination of these.

As organic bases there may be used primary or sec- XVII ondary amines such as the lower alkanolamines, e.g., monoand di-ethanolamine, and polyamines, e.g., ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and hexamethylenediamine. As inorganic bases there may be used the water-soluble oxides and hydroxides, e.g., sodium hydroxide, water-soluble strongly basic salts such as trisodium phosphate, disodium tetraborate, and sodium carbonate, and also ammonia.

As sulphur-containing organic compounds there may be used compounds in which the sulphur atoms are not exclusively present as mercaptan groups and which are mercaptobenzothiazoles and their derivatives, dithiocarbamates, thiuram sulphides, thiorea, disulphides, alkyl xanthogen sulphides and alkyl xanthates.

Examples of siccatives are calcium, copper, iron, lead, cerium, and cobalt naphthenates.

Examples of suitable free-radical catalysts are azodiisobutyronitrile and various peroxides and hydroperoxides such as hydrogen peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, dicumyl peroxide, dilauryl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, and chlorobenzoyl peroxide. Particularly convenient to use are aqueous solutions of hydrogen peroxide.

Yet other catalysts are salts of a heavy metal with an acid having an acid strength (l0g pK) below 5, or chelates of a heavy metal, including chelates which are also salts. By heavy metal" is meant one classified as heavy" in Langes Handbood of Chemistry, revised 10 61, Edition, McGraw-Hill Book Co, at pp. 60 6 1, that is, a metal of group IB, IIB, IIIB, IVB, VB, VIB, VIIB, or VIII, a metal of group IIIA having an atomic number of at least 13, a metal of group IVA having an atomic number of at least 5 l. Preferably the metal is a member of Group IB, IIB, IVB, VB, VIB, VIIB, or VIII, particularly the first series of such metals, i.e, titanium, vanadium, chromium, manganese, nickel and especially iron, cobalt, and copper. Suitable salt-forming, non- 5 drying acids are mineral acids, especially hydrochloric,

hydrobromic, nitric, sulphuric, phosphorous, and phosphoric acids, and organic acids such as chloroacetic,

fumaric, maleic, oxalic, salicylic and, more especially,

citric acid. Suitable chelating agents include those in 0 which the chelating atoms are oxygen and/or nitrogen,

for example, 1,2- and l,3- diketones such as acetylacetone, alkylenediamines such as ethylenediamine, and more particularly ethylenediaminetetra-acetic acid.

The amount of catalyst used can vary widely. In general from 0.1 to 20 percent, and preferably 1 to 10 percent, by weight based on the weight of the ester used is required, although much larger quantities can be used. Curing of the ester takes place more rapidly at a pH of more than 7, e.g., from 7.5 to 12.

As indicated above, curing of the ester is also assisted by using elevated temperatures, e.g., from 30 to as high as C, but temperatures of more than 180C, say, up to 220C, may be encountered if curing is combined with heat-setting. In high humidities also, curing is accelerated.

The ester and the catalyst if used, can be applied to the material in conventional ways. For example, where fabric or yarn is to be treated, they may be padded on from a solution, emulsion, or suspension, or the material may be immersed in a bath. If garments or garment pieces are to be treated then it is convenient to spray them or to tumble them with the solution, emulsion, or suspension.

A particularly effective way of carrying out the process of this invention involves applying the ester by an exhaustion process and comprises immersing the fibres in an aqueous medium containing the ester and heated at from 25 to 95. Exhaustion is favoured by working under acid conditions, the aqueous medium having a pH of from 3 to 6.

It is particularly convenient to use an aqueous emulsion comprising:

i. an ester as aforesaid ii. an emulsifying agent which is preferably nonionic or anionic (for example, compounds containing polyoxyethylene chains),

iii. a protective colloid (such as sodium carboxymethylcellulose, hydroxyethylcellulose and methoxyethylcellulose, and a methyl vinyl ethermaleic anhydride copolymer in the form of an alkali metal or ammonium salt).

The compositions used in the process of this invention may contain bacteriostatic, rotproofing, flameproofing, or wetting agents, and other antisoiling and antistatic agents. They may also contain waterrepellents, such as paraffin wax, and fluorescent whitening agents.

The following Examples illustrate the invention. Unless otherwise specified, parts and percentages are by weight. The esters used were prepared as follows. Thiol A A mixture of Trimer acid Empol 1043 (87.6 g), polyoxypropylene glycol of average molecular weight 425 (127.5 g), thioglycollic acid (27.6 g), toluene-psulphonic acid (2g), and perchloroethylene (300 ml) was heated under reflux in an atmosphere of nitrogen. Water formed during the reaction (11 ml) was removed as its azeotrope with perchloroethylene. The mixture was cooled, and washed with water, the organic layer was separated, and the solvent was evaporated off to leave Thiol A (226.4 g) having a thiol content of 1.09 equiv./kg.

Other thiol esters which were prepared in a similar manner are listed in Table I, except that, in making Thiol N, the toluene-p-sulphonic acid was replaced by 1 ml of 50 percent aqueous sulphuric acid.

TABLE I Thiol content (equiv./kg)

Components Molar Substance Thiol ratio NN -ww-- couroww mphp bw or La TABLE l-Continued Thiol Molar ratio Thiol content (equivJkg) thioglycollic acid hexane-1,2.6-triol Dimer acid Empol 1022" hexane-l,6-diol thioglycollic acid Trimer acid Empol 1043 butane-1.4-diol thioglycollic acid polyoxypropylene triol,

average mol.wt.700 adipic acid butane-1,4-diol thioglycollic acid hexane-1.2.6-triol Dimer acid Empol I022 polyoxypropylene glycol, average mol.wt.425 thioglycollic acid glycerol adipic acid polyoxyethylene glycol, average mol.wt.400 thioglycollic acid l,l,l-trimethylolpropane succinic acid Comerginol 65 thioglycollic acid Trimer acid Empol 1043" butane-1.4-diol 3-mercaptopropionic acid l.l,l-trimethylolpropane adipic acid polyoxypropylene glycol,

average mol.wt.425 3-mercaptopropionic acid 1.1 l -trimethylolpropane adipic acid 2.2-bis(p-(2-hydroxypropoxy) phenyl) propane thioglycollic acid glycerol adipic acid polyoxypropylene glycol.

average mol.wt.42 thioglycollic acid polyoxypropylene triol,

average mol.wt.700 adipic acid 2,2-bis(p-(2-hydroxypropoxy) phenyl)propane thioglycollic acid Trimer acid Empol 1043" polyoxyethylene glycol, average mol.wt.300 thioglycollic acid polyoxypropylene triol, average mol.wt.3000 succinic anhydride 2-mercaptoethanol pentaerythritol-propylene oxide tetrol adduct average mol.wt.650 Dimer acid Empol 1022" Z-mercaptoethanol glycerol phthalic anhydride butane lA-diol thioglycollic acid polyoxypropylene glycol average mol.wt.l000 mercaptosuccinic acid polyoxypropylene glycol average mol.wt.2000 mercaptosuccinic acid polyoxypropylene glycol average m0l.wt.425 mercaptosuccinic acid butanel ,4-diol mercaptosuccinic acid Comerginol 65" mercaptosuccinic acid thioglycollic acid polyoxypropylene glycol average mol.wt.425 mercaptosuccinic acid adipic acid acetic acid -woz--ronui-w Trimer acid Empol 1043 is available from Unilever-Emery N.V., Gouda, Holland. It is a trimerised unsaturated C fatty acid, having an average molecular weight of about 800 and a carboxyl content of about 3.4 equiv/kg. Dimer acid Empol 1022 was obtained from the same source: it is a dimerised unsaturated C fatty acid, having an average molecular weight of about 570 and a carboxyl content of about 3.4 equiv./kg. Comerginol 65 was obtained from Bibby Chemicals Ltd., Liverpool. It has an average molecular weight of about 700, and a hydroxyl value of 155-165. It consists essentially of diprimary alcohols, prepared by catalytic hydrogenation of the methyl esters of long chain aromatic-aliphatic fatty acids, together with, as byproducts, small amounts of monohydric and trihydric alcohols.

EXAMPLE 1 Samples of Crimplene (Registered Trade Mark) scoured polyester fabric were padded with a 1 percent solution of Thiols A, B, C, or D in trichloroethylene to 125 percent uptake. The samples were dried in an oven at 60C for 30 minutes and then allowed to stand overnight at room temperature. All samples had a softer handle than had untreated Crirnplene.

EXAMPLE 2 Aqueous emulsions were prepared containing:

Thiol 500 g Emulsifying agent 50 g Sodium carboxymethylcellulose 5 g Water 445 g The components were mixed at room temperature with a Silverson mixer until uniform emulsion resulted. The emulsifying agent was an adduct of a mixture of C and C aliphatic primary amines (1 mol.) with ethylene oxide (70 mol.)

Emulsions containing Thiols C and D were applied at.

2 percent on weight of fabric on samples of scoured Crimplene at 60C using a liquor ratio of 20:1. The pH of the baths was adjusted to 3.5 with acetic acid to accelerate the exhaustion of the ester onto the fibre. After minutes hydrogen peroxide was added until the concentration of hydrogen peroxide in the bath was 0.3 percent. During the treatment, the solutions, which were originally cloudy, became progressively clearer, showing that the resin emulsion was exhausting onto the fabric.

After a total of 30 minutes the baths were clear and the samples were removed, spun in a spin-drier, and dried in an oven at 60C for 30 minutes. After they had been left overnight at room temperature they were found to have a better handle, compared to untreated samples. This excellent handle was retained when the Crimplene was washed in a solution of 1 g/l surfac tant for 10 minutes at 55C. (The surfactant was an adduct of 1 mol. of nonylphenol with 9 mol. of ethylene oxide).

EXAMPLE 3 Hanks of yarns made of nylon, Courtelle" and Acrilan (polyacrylonitriles), and Tricel (cellulose triacetate) were treated with the emulsions described in Example 2 by the following procedure. The yarns were immersed in the emulsion at 60C adjusted to pH 4.0 ith 0.3 g/l acetic acid using a liquor ratio of 20: 1. After being treated for 30 minutes the yarns were spun in a spin-drier, dried in an oven at C, and finally airconditioned. The handle of the yarns was then assessed.

The nylon and Acrilan yarns had a pleasing softer handle. Although the effect on the Tricel and Courtelle yarns was not quite as outstanding as on the nylon and Acrilan. nevertheless, an appreciably softer handle was obtained.

The words Courtelle, Acrilan", and Tricel are Registered Trade Marks.

EXAMPLE 4 Polyester plain weave fabric was padded with trichloroethylene solutions of Thiols D and E with and without diethylenetriamine. The uptake of Thiol was 2 percent and of diethylenetriamine, if present, 004 per-. cent. The patterns were dried for 10 minutes at 60C and they, and a piece of untreated material were heatset at 195C for 30 seconds. Compared with untreated fabric, all the treated materials had a softer handle and far superior antistatic properties. (The antistatic test consisted of placing the fabric samples about 1 cm above a tray of cigarette ash: untreated material was completely covered with ash whereas there was no pick-up of ash by the treated material). Similar results were obtainable using trichloroethylene solutions of Thiols G Q.

EXAMPLE 5 Samples of scoured Crimplene were padded to 185 percent pick-up with Emulsions 1 18. These emulsions were prepared in the same manner as described in Example 2. The treated patterns were dried for 30 minutes at C. The antistatic properties of the treated fabric were assessed by rubbing the fabrics on a wooden surface and then placing them about 1 cm above a bowl of sawdust and noting the amount of sawdust picked up by the fabric.

Antisoil-redeposition and soil-release properties of treated and untreated samples were measured by the following method. Each pattern was screen printed in a striped pattern with three different soiling compositions, each applied as a band 3 cm wide and separated fromthe adjoining band by an unsoiled strip of the same width.

Soil A was a mixture of used, dirty motor oil (50 percent) and petroleum jelly (50 percent) Soil B was a mixture of lanolin (84 percent and trichloroethylene (16 percent) Soil C was a mixture of sieved vacuum cleaner dust (20 percent), lanolin (60 percent) and trichloroethylene (20 percent).

The soiled patterns were dried in an oven for 1 hour at 40C. Portions of the treated and untreated soiled patterns were then washed for 30 minutes in a washing machine at 40C in a solution containing 2.5 g/l of an anionic detergent. After being well rinsed with water, the patterns were finally dried at 50C for 1 hour. and the soil release and antisoil-redeposition properties were noted.

TABLE II Emulsion Agent Catalyst Antistatic Soil-release Antisoil effect effect redeposition effect I 2% Thiol Good V. Good V. Good 2 2% 'lhiol 0.2% NaHCO Good V.Good V.Good 3 2% 'lhiol Good Good V.Good 4 2% l hiol 02% NaHCO Good Good V.Good 5 2% 'hiol Good Good V,Good 6 2% ghiol 0.2% Nal-lCO Good Good V.Good 7 2% hiol 0.2% SBUD* V.Good Good V.Good 8 2% hiol 0.2% CuSO, Bad Good V.Good 9 2% l 'hiol 0.2% MEA* Good V.Good V.Good 10 2% hiol Good Good V.Good ll 2% hiol 0.2% NaHCO V.Good Good V.Good l2 2% hiol Good F.Good Good 13 2% l hiol 0.2% NaHCO Good F.Good Good 14 2% l 'hiol Good V.Good V.Good l5 2% lhiol 0.2% NaHCO, Good V.Good V.Good l6 2% l olyol 0.2% NaHCO Good Bad Bad l7 2% S Qften- FiGood Bad V.Bad l8 2% S oiten- Good Bad V.Bad Untreated er 2 Bad V.Bad V.Bad

SBUD sodium dibutyldithiocarbamate MEA monoethanolamine V.Good very good F.Good fairly good V.Bad very bad Softener l' was a commercially available cationic softening agent prepared from a long chain fatty acid. a

polyamine. and an unsaturated nitrilc,

Softener 2 was a commercially available polyethylene emulsion.

Polyol A was a polyoxypropylene triol of molecular weight 4000.

Similar results were obtainable using emulsions of Thiols R Z and A.

We claim: 1. A process for improving the handle of synthetic fibres which comprises the steps of l. applying to the fibres, in the absence of keratinous material, a dispersion of a thiol-containing polyester material in water or organic solvent, and

2. curing the polyester material on the fibres, wherein thepolyester material has an average molecular weight of between 400 and 10,000 and is of the formulae:

R CO-O-R -O-CO-RSHL, u

and

HSR-CO-O-R -O CO-R -CO-O-R -O +|n CO- RSH Vlll where R denotes the residue of an acid of 4 to 36 carbon atoms selected from aliphatic, cycloaliphatic, and aromatic dicarboxylic acids after removal of the two carboxylic groups,

R dentoes the residue of a diol of at least 4 carbon atoms selected from aliphatic, araliphatic, and cycloaliphatic diols after removal of the two hydroxyl groups,

R denotes an organic radical containing at least 2 carbon atoms and directly linked through carbon atoms thereof to the indicated mercaptanterminated ester chains.

R denotes the residue of an acid of three to four carbon atoms selected from aliphatic, dicarboxylic acids containing a mercaptan group, after removal of the two carboxyl groups,

m is an integer of at least 1,

p is an integer of at least 2 and no more than 6 and R is a divalent hydrocarbon radical of l to 24 carbon atoms.

2. Process according to claim 1, in which there is used from 0.1 to 10 percent by weight of the polyester material, calculated on the weight of the synthetic fibres treated.

3. Process according to claim 1 in which the synthetic fibres are selected from he group consisting of nylons,

polyesters, polyacrylonitriles, polyvinyl alcohols, and cellulose triacetate.

4. Process according to claim 1, wherein the polyester material is applied to the fibres by an exhaustion process comprising immersing them in an aqueous medium which contains the ester and which is heated to a temperature in the range 25 to C.

5. Process according to claim 1 wherein the polyester material is applied to the fibres in an aqueous medium having a pH of from 3 to 6.

6. Process according to claim 1, wherein a catalyst for curing the polyester material is also applied which is selected from the group consisting of bases, siccatives, oxidising agents, sulfur, sulfur-containing organic compounds, free-radical catalysts, salts of a heavy metal with an acid having an acid strength (-log pK) below 5, and chelates of a heavy metal, including chelates which are also salts.

7. Process according to claim 1, in which the curing of the polyester material is effected at a temperature in the range 30 to 180C.

8. Process according to claim 1, in which he curing of the polyester material is effected at a pH in the range 7.5 to 12.

9. The process of claim 1, wherein the polyester ma terial is selected from the formulae:

I, IV, and V where R is -C,H

II, III, IV, and VIII where R is C H and VII and VIII where R is ified in claim 1. 

2. curing the polyester material on the fibres, wherein thepolyester material has an average molecular weight of between 400 and 10,000 and is of the formulae: R4 - O-CO-R2-CO-O-RSH)p I R4 - CO-O-R3-O-CO-RSH)p II R4 - O - CO-R2-CO-O-R3-O - m CO-RSH)p III R4 - CO - O-R3-O-CO-R2-CO - m O-RSH)p IV R4 - O - CO-R2-CO-O-R3-O - m CO-R2COO-RSH)p V R4 - CO - O-R3-O-CO-R2-CO - m O-R3OCO-RSH)p VI H - O-R3-O-CO-R5-CO -p O-R3-OH VII and HSR-CO-O-R3-O - CO-R5-CO-O-R3-O -m CO-RSH VIII where R2 denotes the residue of an acid of 4 to 36 carbon atoms selected from aliphatic, cycloaliphatic, and aromatic dicarboxylic acids after removal of the two carboxylic groups, R3 dentoes the residue of a diol of at least 4 carbon atoms selected from aliphatic, araliphatic, and cycloaliphatic diols after removal of the two hydroxyl groups, R4 denotes an organic radical containing at least 2 carbon atoms and directly linked through carbon atoms thereof to the indicated mercaptan-terminated ester chains. R5 denotes the residue of an acid of three to four carbon atoms selected from aliphatic, dicarboxylic acids containing a mercaptan group, after removal of the two carboxyl groups, m is an integer of at least 1, p is an integer of at least 2 and no more than 6 and R is a divalent hydrocarbon radical of 1 to 24 carbon atoms.
 2. Process according to claim 1, in which there is used from 0.1 to 10 percent by weight of the polyester material, calculated on the weight of the synthetic fibres treated.
 3. Process according to claim 1 in which the synthetic fibres are selected from he group consisting of nylons, polyesters, polyacrylonitriles, polyvinyl alcohols, and cellulose triacetate.
 4. Process according to claim 1, wherein the polyester material is applied to the fibres by an exhaustion process comprising immersing them in an aqueous medium which contains the ester and which is heated to a temperature in the range 25* to 95*C.
 5. Process according to claim 1 wherein the polyester material is applied to the fibres in an aqueous medium having a pH of from 3 to
 6. 6. Process according to claim 1, wherein a catalyst for curing the polyester material is also applied which is selected from the group consisting of bases, siccatives, oxidising agents, sulfur, sulfur-containing organic compounds, free-radical catalysts, salts of a heavy metal with an acid having an acid strength (-log pK) below 5, and chelates of a heavy metal, including chelates which are also salts.
 7. Process according to claim 1, in which the curing of the polyester material is effected at a temperature in the range 30* to 180*C.
 8. Process according to claim 1, in which he curing of the polyester material is effected at a pH in the range 7.5 to
 12. 9. The process of claim 1, wherein the polyester material is seleCted from the formulae: I, IV, and V where R is -CtH2t-II, III, IV, and VIII where R is -CrH2r-; and VII and VIII where R5 is
 10. Synthetic fibrous material, free from keratinous material, bearing thereon an polyester material as specified in claim
 1. 